More than 40 per cent of lawmakers in India's new parliament face criminal charges — some as serious as murder and rape — and the list is growing, an electoral reform group said on Saturday.

One member of parliament for the opposition Congress party is battling 204 cases including manslaughter and robbery, the Association of Democratic Reforms (ADR) said.

At least 233 of the 543 members named as winning seats on Thursday face criminal proceedings, according to the ADR, whose election chief Anil Verma said there is a “disturbing trend” in parliament that “is bad for the democracy”.

The ADR said it studied the records of 539 of the winners and found that the number facing criminal cases was the highest since it started studies in 2004.

The report said 116 of the 303 lawmakers from Prime Minister Narendra Modi's Bharatiya Janata Party (BJP) landslide win face charges, including one for terrorism.

Twenty-nine of the 52 Congress MPs face cases. Dean Kuriakose from Idukki, in Kerala state, faces 204 criminal cases.

The ADR said the number of lawmakers facing grave criminal cases had more than doubled in a decade — including 11 murder cases, 30 manslaughter charges and three accused of rape.

Indian laws bar people from contesting an election if they have been convicted while in office for crimes that carry jail terms of two or more years, with some exceptions depending on the crime.

Candidates standing for office for the first time are allowed to have a conviction.

None of the 185 lawmakers from the previous parliament who faced criminal cases was convicted. Many have returned for a new term.

Firebrand Hindu nationalist nun Sadhvi Pragya Thakur, a newly elected BJP MP, faces a terrorism charge over a 2008 attack near a mosque that killed six people. She denies the charges and says she was framed by a previous Congress government.

Parties often brush off charges against their candidates by saying they were victims of political vendettas. This year India's election commission made it mandatory for candidates to publish details of their criminal records during the campaign period.

The ADR campaigns to bring accountability into Indian politics and successfully petitioned the Supreme Court to make candidates file their educational, financial and criminal records.

Verma said the political class sought to avoid reform. But he added: “We will continue to legally fight this menace and demand that courts bar candidates facing criminal charges.”