Two IVF clinics run by Britain’s most successful fertility doctor were raided yesterday by regulators and police following allegations that he treated patients without a valid licence.

Inspection teams from the Human Fertilisation and Embryology Authority (HFEA) were granted a warrant to search the two London clinics run by Mohammed Taranissi to determine whether he has committed a criminal offence.

Mr Taranissi, whose personal wealth is estimated at £38 million, operates the Assisted Reproduction and Gynaecology Centre (ARGC) and the Reproductive Genetics Institute (RGI).

The ARGC has long topped league tables for IVF success rates and has an active licence. The licence held by RGI has expired. If there is evidence that he treated patients illegally he could become the first doctor to be prosecuted.

The teams are also investigating allegations about the types of therapy he recommends and the information given to patients.

Mr Taranissi vigorously denied any wrongdoing and said that he had co-operated fully with the inspections. He accused the HFEA of changing its procedures to refuse the RGI a licence. The only patients treated since its application for renewal was turned down were seen with the authority’s knowledge and approval, he said.

Angela McNab, chief executive of the HFEA, said: “Since January 2006, the RGI has not had a licence. Providing treatment in a centre which does not have a licence is potentially a criminal act.” The HFEA needed a warrant because the RGI’s licence had run out and the regulator did not have an automatic right to inspect it.

The RGI’s licence expired in December 2005, but for the first six months of 2006 it operated under “special directions” from the HFEA.

In June, Mr Taranissi was offered a three-year licence, on condition that he transfer no more than two embryos to patients aged over 40.

He accepted the offer, but indicated that he wished to make representations about the condition. The HFEA interpreted this as a refusal of the licence. The offer was then withdrawn.

Mr Taranissi said that he then stopped taking new patients at RGI and finished treating patients whose cycles had begun. This was done with the knowledge and approval of the HFEA, he said.

He told The Times: “It is very odd the way they have portrayed the licence situation. All of a sudden, they said to me because you have made representations, you have effectively refused the licence.

“There is no issue of patient safety here, it is about the interpretation of a signed paper. It is different from a backstreet clinic, where there is a very serious issue of patient safety.”

The HFEA said that its action was taken independently of allegations made against Mr Taranissi by the BBC One Panorama programme last night. It claimed that a young undercover reporter had been offered IVF at the ARGC even though neither she nor her partner had a history of infertility.

Mr Taranissi said that the BBC failed to report visits by three other reporters who were given appropriate advice, and that the 26-year-old reporter had been seen by a junior doctor no longer with the clinic.

He said that her notes indicated that the doctor had discussed options including natural conception with the woman and that his comments had been taken out of context.