Dr Richard Freeman suffered "constant attrition" from former British Cycling performance director Shane Sutton, the medic's tribunal has heard.
Former British Cycling and Team Sky doctor Freeman is being assessed for his fitness to practise after admitting 18 of 22 charges against him.
He denies ordering banned substance testosterone to the National Cycling Centre in 2011, knowing or believing it was to boost an athlete's performance.
Freeman claims he was bullied into ordering the package for Sutton, which the Australian denies.
On another extraordinary day at the tribunal in Manchester, former British Cycling physio Phil Burt described the "deteriorating relationship" between Dr Freeman and Sutton, and said the pair had a "monumental falling-out" over payment of a plane ticket in 2015.
In other evidence to the tribunal:
- Burt said he received a "veiled threat" from Sutton, but he wasn't bullied
- Sutton accused Burt and Freeman of being whistleblowers in Jess Varnish's allegations against British Cycling
- It was alleged by Dr Freeman's defence that Sutton asked the doctor to make up a back problem to support his case to drop Varnish from the cycling team.
- Burt said the package containing the testosterone also contained a contraceptive pill but no Viagra.
- Burt admitted opening Dr Freeman's packages, but did not want to know what was inside them.
Burt, who left British Cycling in 2018, told the tribunal he opened the package delivered to the National Cycling Centre in 2011, which containing 30 sachets of Testogel.
He said of Sutton's behaviour towards Dr Freeman: "There were verbal confrontations, passing remarks, constant attrition.
"One example sticks in the mind after the 2015 falling-out."
He then reported Sutton as saying: "The doc looks like he's losing weight, I've got him where I want him."
Burt continued: "All people heard that. At that time, Shane was just riding on [Freeman's] case on the time, chasing him. I witnessed it. These problems were historical and had gone on for a long time."
- Dr Steve Peters doubts testosterone claims
- Ex-British Cycling coach storms out of medical tribunal after 'doper' claim
- Freeman 'bullied by Sutton to order testosterone' hearing told
Burt also told the tribunal how the pair's relationship broke down after Dr Freeman wanted to return early from the Track World Cup in Colombia in 2015.
"Richard had a bereavement and wanted to go home. He arranged a flight, couldn't get it so got the next one," Burt said. "Richard thought it was reasonable that British Cycling would pay for it, but Shane didn't and they fought over it for a long period of time. They couldn't let go."
Dr Freeman has accused Sutton of bullying him into ordering the Testogel to treat the Australian's alleged erectile dysfunction.
Burt said he himself had not been bullied by the Australian, who stormed out of the tribunal on Tuesday after being labelled by Freeman's defence lawyer Mary O'Rourke as a "liar, doper and a bully".
O'Rourke also asked Burt about an interview he had given to the Anne-Marie Phelps report into the culture at British Cycling in 2017. In it, Burt admitted to having "difficult conversations and some of them are not very pleasant at all. I received a veiled threat but not bullying".
'Freeman stood up to Sutton on Varnish case'
There were also several revealing exchanges regarding former British Cycling team member Varnish, who said she was victim of a "cover-up" regarding her sexism allegations while in the team.
She was dropped by the body in 2016, and a subsequent British Cycling investigation found that Sutton had used sexist language towards Varnish, but cleared him of bullying.
At the tribunal, O'Rourke claimed Sutton had wanted Dr Freeman to say that, such was the nature of Varnish's back problem, she would not have won a medal in any event. She added that Dr Freeman refused Sutton's demand.
Burt told the tribunal: "Richard never mentioned that to me, but I can imagine him standing up to that."
The tribunal also heard O'Rourke describe Sutton's reaction to claims Dr Freeman and Burt might have been whistleblowers in Varnish's case against British Cycling.
"I saw Sutton and he accused the two of us in the corridor," Burt said. "I said I had no idea what you're taking about. It was quite unsettling - he was quite conciliatory, saying we've got to get on.
"Richard said Shane had threatened to check his phone and laptop."
Burt gives conflicting evidence on packages
Earlier in proceedings, the tribunal heard the contents of the package delivered to British Cycling in 2011 described, and the drugs that were also on the order.
On Thursday, former British Cycling head of medicine Dr Steve Peters had told the tribunal he had been "led to believe" that the delivery also contained Viagra.
But O'Rourke said on Friday that was not the case. There were five items on the invoice, including the Testogel. The other medication was several packets of the contraceptive pill, an asthma drug (Montelukast), a facewash for acne, and an antihistamine (Valoid).
Burt gave conflicting evidence about whether it was normal for him to open the delivery on the day the testosterone arrived at the Manchester velodrome.
He said: "I wouldn't open Richard's parcels because I didn't want to understand what he's getting and what or who it's for."
But he later told the tribunal: "We did open each other's packages."
The hearing is adjourned until Wednesday.