A controversial Italian fertility doctor who won international fame for helping women in their 60s get pregnant has been arrested and accused of taking a patient’s egg without her consent.

Severino Antinori was placed under house arrest after being detained at Rome’s Fiumicino airport on Friday night.

His lawyer told Agence France-Presse the charges were absurd and that the allegations were part of an attempted extortion. The doctor denied the allegations on Sunday.

“I have pains in my chest, I could have had a heart attack,” Antinori, 70, told the AGI news agency. “I am very ill because of this unjustified arrest. Do they want me dead? I am an honest man. I’ve never robbed eggs from anyone and while all this is going on the embryos that have been sequestrated are dying.”

At the heart of the case is a claim by an unidentified Spanish nurse who recently began working in Antinori’s clinic in Milan.

The 24-year-old woman told police she was supposed to be treated in the clinic for an ovarian cyst, but that shortly before receiving treatment, she had her mobile phone taken away and was forcibly immobilised, placed under anaesthesia and operated on without her consent.

The woman called police after the procedure was completed. Antinori, who is known for having assisted the pregnancies of women in their 60s and for his support of cloning as a means of fertility treatment, has had his licence suspended for a year and has been placed under house arrest while the investigation continues.

He faces charges of aggravated robbery and causing personal injury.

Antinori’s lawyer not only claimed his client was being extorted, he also told the Ansa news agency that the alleged victim had signed consent forms for the procedure and was “conscious of the choice she was making and that it did not pose any problems”.

While IVF procedures vary depending on the patient, in most cases a woman undergoing egg retrieval first takes fertility drugs to produce more than one egg and increase the chances of pregnancy. The timing of the procedure is usually closely monitored and simulated to replicate the period in which an egg can be successfully fertilised with sperm.

The allegation is likely to further inflame an already-sensitive topic in Italy: infertility and the means women use to become pregnant. Italy passed some of the harshest restrictions against IVF in the world under Silvio Berlusconi, the former prime minister, including a law that forbade anyone but married heterosexual couples from seeking the treatment. The controversial 2004 law reflected the influence of the Catholic church, which is vehemently opposed to IVF.

Italy’s highest court in 2014 reversed one of the harshest elements of the law by making it legal for patients to use donated eggs and sperm. But the treatment is still restricted to married heterosexual couples.

Donata Lenzi, from prime minister Matteo Renzi’s Democratic party, said the arrest of Antinori was “extremely serious” because it indicated the existence of a “market in eggs that will not stop at anything”.