A man has been arrested for allegedly raping a 21-year-old Irish woman in the Indian city of Kolkata, police said Monday.

The victim, an engineering student who is doing charity work with a Darjeeling-based NGO, accused a 25-year-old local businessman of drugging her before raping her in his south Kolkata home following a night out with friends, reports AFP.

According to the woman’s complaint, she met Sujay Mitra while strolling around the New Market Area and invited him to celebrate her birthday on Friday night.

Mitra invited her to his home after the party for a cup of tea. She immediately felt drowsy after consuming the drink and passed out on Mitra’s bedroom, where she was allegedly assaulted in a semi-conscious state.

The woman was sent for a medical examination at the state-run SSKM hospital. The test results showed no signs of rape but found a few minor injury marks on her back, reports The Times of India.

“My client is a patient of pancreatitis and is not permitted to consume alcohol, leave alone drugs. He is innocent,” said Mitra’s lawyer, Dibyendu Bhattachary.

The latest incident has once again raised questions on the security of foreign women tourists in India. The number of female tourists visiting the country had dropped by 35% following a series of sexual attacks, according to the Associated Chambers of Commerce and Industry of India.