Secondary ticketing websites are enabling professional touts with "preferential schemes" for power sellers, MPs have been told.
Ticket fraud expert Reg Walker claimed that some sellers were paid in advance, and given powerful software to manage their inventories.
He said sites were dependent on "bad actors" who used computers to harvest "and resell high volumes of tickets".
"Secondary sellers are covering [for touts] in some cases," he added.
Mr Walker is head of the Iridium Consultancy, which tackles ticket fraud for a number of major UK venues, including London's O2 Arena.
Speaking to MPs on the Culture, Media and Sport select committee, he said that some sellers were "courted" by sites like GetMeIn, Viagogo and Stubhub.
"And the reason is there's a finite amount of these people that harvest tickets in bulk."
Stubhub, which is owned by eBay, also gave evidence, and insisted that they carried out "due diligence on all our sellers".
However, "we do not police or monitor our site and we are not required to do so", said Paul Peake, head of the company's legal department.
You Me At Six singer Josh Franceschi was among those calling on MPs to clamp down on online ticket touts.
The 26-year-old said computer programmes known as bots, which bulk-buy tickets the second they go on sale, should be made illegal.
Those tickets often ended up being sold at inflated prices on the secondary market, he added.
"Money is been taken out of the industry and put into the hands of people who are only concerned with lining their own pockets.
"The main losers here are the fans of live music."
However, Mr Walker revealed that it is not just professional touts who exploit the system.
He said tickets for a recent Michael Buble tour had been handed directly to secondary ticketing websites by one of the star's associates.
"I believe that was done without the artist's knowledge," he said, "but it makes me wonder if there are other artists that this is happening to."
Arctic Monkeys' manager Ian McAndrew said he had been offered similar deals in the past.
"I have often been approached by one of the big four resale sites asking to enter into an arrangement where I give them inventory in return for participation in the resale profit," he told MPs.
"That is a proposal I've refused on a number of occasions - but I can understand how that would be a temptation for some who want to maximise profits for a show."
Mr McAndrew also called for greater transparency from primary sellers. He said it is often "unclear" how many tickets will be available when a tour goes on sale - as venues, promoters, bands and sponsors often receive their own allocation to distribute separately via pre-sales and promotions.
"The number of tickets that then go on sale at general sale is unknown, is unclear to us. But there is increasing evidence to suggest it is far smaller than it should be."
A limited supply of tickets helped fuel the secondary market, he said.
Chris Edmonds, Chairman of Ticketmaster UK, confirmed that up to 50% of tickets could already have been allocated when the general sale begins.
"We can have hundreds of thousands of consumers queuing on our site to buy tickets for an event, with no real visibility of how many tickets are left," he said.
"Wherever you have an instance where demand is beyond supply, it creates a concern and a frustration and a disappointment."
A government review of the ticketing market was conducted earlier this year by Professor Michael Waterson, economics professor at Warwick University.
Call for variable pricing
Speaking on Tuesday, he said he was not in favour of banning the secondary ticketing market, but supported the idea of outlawing "bots".
He also called for pop concerts to introduce variable pricing - as seen in opera and theatre - in an effort to deter touts.
Labour MP Sharon Hodgson, co-chair of the all-party parliamentary group on ticket abuse, told the BBC: "Fans cannot be fleeced any longer.
"I hope the government will realise that sitting on their hands cannot go on and will listen to the chorus of concerns coming from the industry, fans and Parliamentarians and finally take action."