A retired French archbishop is under investigation from judicial and church authorities for what he called "an inappropriate gesture" towards an adult young woman at the end of the 1980s.

Monseigneur Jean-Pierre Grallet, 81, the retired former archbishop of Strasburg, said in a statement on Wednesday that he had been informed this summer that the woman had filed a complaint against him. 

"From now on, as I await the conclusions of church and civil investigations, I will refrain from speaking in public," Grallet said, adding that he regretted his actions back then and that he has written to the woman to ask for her forgiveness.

He gave no detail about what kind of behaviour he is under investigation for. 

Last week, French Cardinal Jean-Pierre Ricard said he had abused a 14-year-old girl decades ago and would withdraw from his functions.

In total, 11 bishops or former bishops are currently the subject of abuse investigations, Eric de Moulins-Beaufort, head of the French bishops' conference, said last week. 

Last year, an independent investigation said French clergy had sexually abused more than 200,000 children over the past 70 years, and its authors said the Catholic Church had turned a blind eye for too long.