Sean Lien, the son of Taiwan's former vice-president Lien Chan who made an ice-breaking trip to China in 2005, announced Monday he is seeking to run for mayor of Taipei.

He said he would contest primaries of the ruling Kuomintang (KMT) party to try to secure its nomination for November's election.

"After pondering for a long period of time, I here announce that I'm running for the Taipei mayoral election," he told reporters in the capital.

Following the announcement, the China-sceptic opposition Democratic Progressive Party (DPP) demanded Sean Lien clarify what it claims are cosy ties between his family and Chinese leaders.

The DPP alleges the family has invested in China and cashed in on Lien Chan's influence following his key trip almost a decade ago.

Sean Lien Monday denied investing in China, and insisted any business activity was "in line with the law".

The 44-year-old worked for years in business. He said he decided to enter politics after he was shot by a lone gunman at a Kuomintang election rally in 2010.

Sean Lien was rushed to hospital for emergency surgery. His attacker, who later told police he had shot the wrong man, was sentenced to life in prison.

"After (my) suffering three years ago, I started to think why God had kept me in the world. Perhaps He wants me to stay to help those people in need?" he said.

Sean Lien, who was born into one of Taiwan's richest political families, insisted he was not running for money or power.

If elected, he has promised to donate his mayoral salary to charity following a precedent set by New York's Michael Bloomberg.

Lien Chan became the first Kuomintang party leader to visit China in 56 years when he met President Hu Jintao in 2005 to formally end hostilities with the communists.

The meeting paved the way for the detente launched in 2008 by President Ma Ying-jeou, who was re-elected in 2012.