KUALA LUMPUR - One of Malaysia's longest serving Cabinet ministers S. Samy Vellu is not mentally fit to manage his affairs due to dementia, his son S. Vell Paari has claimed.

Datuk Seri Vell Paari has filed an application to seek a court declaration that his 82-year old father - a political icon in the late 1980s and into the 1990s - isn't able to defend himself after legal cases were filed against him, local media reported.

His son said Tun Samy Vellu was diagnosed with Alzheimer's disease two years ago.

"Because he has dementia, my father has poor recall and registration of certain events. Consequently, he needs to be assisted in managing his personal and financial affairs," Mr Vell Paari said in a statement on Monday (Dec 9).

Mr Vell Paari said his mother Toh Puan R. Indrani and younger sister S. Mangayerkarasi supported the move to seek a court declaration of his father's mental capacity.

Mr Samy Vellu was president of the Malaysian Indian Congress (MIC), a key component of BN, for a record 31 years until 2010.

He dominated Indian politics in Malaysia for decades after joining the party in 1959.

He was also a key loyalist of Tun Mahathir Mohamad who was prime minister for 22 years to 2003 when he was leading the BN coalition.

Mr Samy was a long-serving works minister, and also served as minister for energy, communications and posts, for a total of 29 years until he lost his parliamentary seat in the 2008 general election.

His son Mr Vell Paari, 54, denied speculation that the suit, filed on Dec 2, was meant for him to gain control of his father's assets. Mr Vell Paari is secretary-general of the MIC, which remains a member of BN, and has one seat in Parliament.

"My mother, sister and I have observed the progressive deterioration of my father's cognitive ability since 2017," the statement said, as quoted widely by local media.

Mr Vell Paari added that one Professor David Ames, a consultant psychiatrist from Victoria, Australia, had attended to his father and diagnosed him as having dementia in the same year.

Mr Vell Paari said that his father's "former mistress", whom he identified only as Meeriam, had initiated legal proceedings against him and his father at the Ipoh High Court.

The Star reported that the suit was filed by one Meeriam Rosaline Edward Paul in the Ipoh Courts.

Said Mr Vell Paari: "I would like to state that Meeriam's claims are being disputed. Due to my father's condition, he is unable to give proper orders to his lawyers and unable to affirm affidavits on his own name."