Lib Dem drugs minister Norman Baker said in 2001 that cannabis was no more harmful than alcohol or tobacco

Norman Baker, the new drugs minister, has previously said cannabis is "no more harmful than alcohol or tobacco", a sign that he could bring a more liberal approach to his role at the Home Office.

The Liberal Democrat minister will take over a review of drugs policy that was being conducted by Jeremy Browne, his more right-leaning predecessor in the role.

Baker's appointment to work alongside Theresa May, the home secretary, has raised eyebrows among his colleagues because he once wrote a book suggesting that the UN weapons inspector Dr David Kelly was murdered by an Iraqi hit squad and that the incident was covered up by MI5.

However, the minister said on Tuesday he had "closed the door" on Kelly's death, which was ruled a suicide by an official inquiry. He told BBC Radio 4's World at One programme he intended to concentrate on his policy briefs, which include drugs, alcohol, homelessness, antisocial behaviour, online exploitation of children and organised crime.

Baker expressed strong opinions on drugs policy when Tony Blair announced he would downgrade cannabis to class C in 2001. Gordon Brown later upgraded it back to class B.

At the time of Blair's decision, Baker told his local newspaper the Sussex Express: "I would like to see resources concentrated on hard drugs, which cause such damage to society, without police being distracted by having to deal with millions of cannabis users who use a drug which is no more harmful than alcohol or tobacco.

"The government move is a sensible one, but it doesn't go far enough. There should be a wide-ranging inquiry into the use of illegal drugs in general and the legislation dealing with them. I called for the softening of the law against cannabis some years ago and was shot down in flames for it. Now the government seems to be recognising that what we said seven or eight years ago had some merit."

Asked on Tuesday whether he still believed cannabis was no more harmful than alcohol or tobacco, Baker said in a statement: "I do not encourage anyone to take any harmful substances. Cannabis has become more potent over the years and long-term use has been linked to increased risks of mental illness.

"Our current drug laws are based on the best available evidence and I will be continuing Jeremy Browne's report into international drug policy comparisons as part of my work as the Home Office minister for crime prevention."

Earlier on World at One, Baker said: "The key thing is I don't encourage any use of drugs or any harmful substances. I hope people will drink less and smoke less, as a matter of fact.

"Where we want to get to is making sure where people do use drugs they can be persuaded out of that habit and we don't end up with people committing crime in order to feed their habit."

Before he was fired in the reshuffle, Browne had been gathering evidence from about 10 other countries on their drug policy, including Portugal's efforts to reduce drug use by removing criminal penalties for personal possession but not making them legal.

He was tasked by the home secretary with "looking at a number of countries that cover a spectrum of approaches to drug policy and assessing their effectiveness in cutting drug use and reducing harm".

Browne had expressed doubts about relaxing laws on cannabis, claiming the drug was "getting much stronger and potentially more harmful". May has said the government "does not believe there is a case for fundamentally rethinking the UK's approach to drugs".