Image copyright AFP/Getty Image caption Bill Cosby strongly denied a series of sexual assault allegations dating back to the 1970s

A prestigious African-American college has discontinued a professorship funded by the comedian Bill Cosby, following allegations that he assaulted several women.

Spelman College in Atlanta, Georgia, had provisionally suspended the position last year when the allegations first emerged.

It is now returning what remains of the original $20m (£13m) donation.

Mr Cosby denies any wrongdoing and has not been charged with any crime.

The Cosby family donated the money to the women's college in 1988 and the endowed professorship was established in the name of Mr Cosby and his wife, Camille.

Mr Cosby, 78, is facing a series of historic sexual assault allegations dating back several decades.

'Recreational drug'

Recently released court documents from a 2005 civil case show he had admitted obtaining sedatives to give to women before sex.

But Mr Cosby's lawyers said he was only one of many people who introduced the sedatives - Quaaludes - into their "consensual sex life in the 1970s".

They said that at no point had Mr Cosby admitted to having any non-consensual sex or giving any women drugs without their knowledge.

"Quaaludes were a highly popular recreational drug in the 1970s, labelled in slang as 'disco biscuits', and known for their capacity to increase sexual arousal," a statement said.

Mr Cosby's legal team is attempting to stop a judge unsealing the full set of documents from the case, including the confidential settlement agreement.

More than 12 women have accused Mr Cosby of sexual assault, but he has denied all of the claims.

Timeline of allegations against Bill Cosby

2002: Lachele Covington, a 20-year-old actress, reportedly files a police report saying she had been inappropriately touched. No further action was taken.

2005: Andrea Constand sues Mr Cosby for sexual assault. The case is eventually settled out of court in 2006.

2014: Over the year, dozens of women make public accusations that Mr Cosby sexually assaulted them. Live shows are cancelled across the country amid protests

November 2014: TV network NBC scraps plans for a new show with the comedian following allegations by TV presenter Janice Dickinson that he had assaulted her in 1982. Repeats of the Cosby Show are also pulled from cable TV

December 2014: Judy Huth sues Mr Cosby for molesting her in 1974 when she was 15 years old. Mr Cosby counter-sues, claiming she is trying to extort money from him

May 2015: Mr Cosby speaks publicly about the allegations for the first time. "I can't speak; I just don't want to argue; I don't talk about it," he told ABC News.

July 2015: Court papers made public from Constand's 2005 civil case reveal Mr Cosby admitted obtaining sedatives with the intent of giving them to women he wanted to have sex with.