The father of missing Claudia Lawrence has died without ever knowing what happened to his daughter.
Peter Lawrence, who was 74, died on Thursday at St Leonard's Hospice in York following a short illness, his family said in a statement.
His death comes 12 years after his daughter vanished in the city.
Police believe Claudia - who was 35 when she was last seen on 18 March 2009 - was murdered but her body has never been found.
Mr Lawrence's family said in a statement: "It is sad that nearly 12 years after Claudia's disappearance from York, Peter never found out what has happened to her.
"He was a very private person thrust into the full glare of the media, and despite a tireless campaign to find her he also selflessly devoted himself to helping others with missing relatives through the charity Missing People."
Mr Lawrence campaigned for the Guardianship (Missing Persons) Bill, also known as Claudia's Law, which was passed in April 2017.
Claudia's Law, which came into force in July 2019, allows relatives to take control of their missing loved ones' financial matters.
Mr Lawrence, a retired solicitor, said it was an "absolutely marvellous feeling" to see the proposals clear a major hurdle in the law-making process.
In 2018 he was appointed an OBE in the Queen's Birthday Honours in recognition of his tireless campaigning for change after his daughter's disappearance.
Mr Lawrence's family said: "Despite Peter's death, the message remains the same - where is Claudia?
"Anyone with information should contact North Yorkshire Police on 101."
Mr Lawrence described being "hugely disappointed and depressed" when in January 2017 detectives said they were scaling back the investigation.
Miss Lawrence was reported missing after she failed to turn up for work at the University of York.
Police previously said they "strongly suspect key and vital information" which would offer a breakthrough was being "withheld".
Nine people have been questioned as part of the investigation, but no charges have ever been brought.