Sri Lanka's top judge attended parliament on Friday for the start of a process in which she is expected to be impeached over alleged financial misconduct, witnesses and officials said.

Chief Justice Shirani Bandaranayake, 54, left the Superior Courts complex and drove to the national parliament accompanied by a lawyer to face an 11-member parliamentary committee probing 14 charges of financial and official misconduct.

The lawmakers are pressing ahead with the hearing despite a non-binding Supreme Court order for parliament to delay while legal challenges to the impeachment process are heard.

Rights groups have said the impeachment is the latest sign of efforts by President Mahinda Rajapakse to tighten his grip on power after crushing the Tamil Tiger separatist rebels in 2009 at the end of a decades-long war.

The impeachment move followed a Supreme Court decision last month that effectively scuppered a bill giving more powers to the economic development minister, who is the president's younger brother Basil.

Bandaranayake, whose husband was also charged recently with corruption while holding a political appointment as the head of a state-owned bank, has denied the financial wrongdoing alleged in the impeachment.

The move to sack her was initiated by the ruling United People's Freedom Alliance.