The father of the young man who sent obscene messages to Sharmistha Mukherjee, daughter of President Pranab Mukherjee and a Congress leader, has apologised, saying that his son is undergoing psychiatric treatment, she said on Tuesday.

The Delhi Congress leader advised the father of Partha Mandal to surrender his son to the local police and let the court decide if he is actually "sick".

"Partha Mandal's father has written to me on FB (Facebook) claiming that his son is under psychiatric treatment and apologising for his behaviour," Sharmistha Mukherjee wrote on her facebook account on Tuesday.

"In this case, I advised the father to ask his son to surrender to local police. Let the court decide if he is actually 'sick' or as we say in Bengali, a 'sheyana pagol'," Sharmistha Mukherjee said.

The Congress leader had publicly named and shamed Partha Mandal on facebook for sending obscene messages to her on the intervening night of Friday and Saturday.

"One consequence of this episode of 'naming and shaming' and tagging the person has been, in this case, that his family and friends have become aware of his loathsome behaviour," the Congress leader added.

She had also filed a complaint with the Cyber Cell of the Delhi Police on Saturday under various sections of the Indian Penal Code and Information Technology Act as she found the messages of Partha Mandal "indecent and intimidatory".

The Delhi Congress chief spokesperson, who unsuccessfully contested the Delhi Assembly elections in 2015, also urged every woman facing this problem to follow the "naming and shaming" practice.