Three of Mario Batali’s Las Vegas Strip restaurants are to close, amid allegations of sexual misconduct including rape and the famed chef’s efforts to counter them.

Last week, Batali & Bastianich Hospitality Group partner Joe Bastianich sent a letter to nearly 300 workers at Carnevino, B&B Ristorante and Otto Enoteca e Pizzeria, announcing the closures. The news was confirmed by Las Vegas Sands, which owns the properties in which the restaurants are sighted.

The announcement came days after police in New York confirmed that they were investigating a claims made by a woman who said Batali drugged and sexually assaulted her in 2005.

The unidentified woman told the CBS show 60 Minutes the incident took place at the Spotted Pig, in New York’s West Village. She said she passed out after drinking with Batali and when she woke found scratches on her leg and semen on her skirt. The woman called a rape crisis hotline and had a rape kit taken at a hospital, but did not file a police complaint.

Batali is also alleged to have drugged and sexually assaulted a woman at his restaurant Babbo in 2004. In that alleged incident, reported by the New York Times, the woman said she had been drinking at the bar and went upstairs to use the bathroom. Her next memory, she said, was waking up as Batali was raping her.

Batali, 57, stepped down from daily operations at his restaurant empire in December, after four women accused him of inappropriate touching. He apologised for those incidents, telling Eater “much of the behavior described does, in fact, match up with ways I have acted”.

He “vehemently denies” allegations of nonconsensual sex.

The restaurant closures continue what appears to be an unraveling of a once-formidable business empire. Last week, B&B Hospitality Group said it was “actively negotiating” to buy the chef out of his restaurant interests, which include Del Posto and Babbo in New York and dozens of others across six states.

Thanks to the supermarket-restaurant chain Eataly, Batali’s business took in more than $200m in 2012. Last week, Eataly said it was looking to “compel the divestiture” of Batali’s “small, minority interest”. Eataly has removed Batali’s branded products from its shelves.

The TV network ABC has said Batali will no longer appear on its morning show, The Chew. The Food Network also halted production on Molto Mario, the show that helped establish Batali as a household name. Last week, Batali was reported by the Times to be imagining a comeback.