Drug addicts desperate to kick the habit are forced to commit criminal offences to get a place in rehab, the father of singer Amy Winehouse told MPs today.

Mitch Winehouse, who is making a documentary on drug use, was giving evidence to the home affairs select committee on the cocaine trade. He said drug users struggling to get clean had to wait at least a year for treatment while addicts committing other crimes were often given places in residential rehabilitation centres.

Amy Winehouse has struggled with drink and drug problems in recent years. The singer of songs such as Rehab recently returned to live performing after an eight-month stay in the Caribbean and her divorce from husband Blake Fielder-Civil in July.

Her father said he had heard stories of people trying to steal their way into rehab after finding themselves unable to get treatment through the normal channels.

"Anecdotally, people are definitely committing offences so they can have a chance, and it's only a chance, of receiving treatment," he said. "The biggest impact on families is that there is very little help available to them, especially if their relative is a non-offending addict.

"Their first port of call will be the GP and then they will refer them on to the local health authority.

"The problem that we have found in our research in London is that there is a period of a year before any treatment can be given. It's very difficult, and the reason for this is the majority of funding is taken up by the criminal justice system."

He said that this had happened to his son-in-law – Fielder-Civil – when, as part of a sentence, the judge offered him a period in residential rehab. "So we have a situation where a non-offending addict and his family are looking for help and there are very few resources available to them."

However, Winehouse's claims were dismissed by the National Treatment Agency for Substance Misuse (NTA), which is part of the NHS.

It said waiting lists for drug treatment in England had fallen to an average of one week, while 93% of people got the help they needed in three weeks, even when a stay in a residential rehabilitation centre was required. The agency added that, in 2008-09, 207,580 adults in England were treated for drug abuse.

Paul Hayes, the NTA's chief executive, said: "Drug treatment in England has never been more available to members of the public who need it. We think it is important that the public knows that, if they or a family member needs help, they can get it on the NHS."

Earlier, the committee had asked two drug policy experts about the scale of Britain's cocaine problem.

Professor Neil McKeganey, from the centre for drug misuse research at Glasgow University, described the rise in the use of cocaine as "very worrying". He said: "In my view, cocaine is one of the most serious threats we are facing. It's not yet on the scale of heroin but it is changing dramatically in terms of misuse."

Asked about the extent to which the behaviour of drug-taking celebrities could be blamed for drug use among the young, he said: "We wouldn't have one of the largest drug problems in Europe if our drug prevention policies had been successful. I think that [celebrity drug use] doesn't help matters, but it doesn't have a substantial impact on young people taking drugs."

Steve Rolles, head of research at the Transform Drug Policy Foundation, agreed. "It's a red herring and reflects politicians' concerns with tabloid obsessions more than anything else," he said. "There are drug wars in Colombia and we must move on from what Amy Winehouse does on her weekends."