Lembah Pantai MP Nurul Izzah Anwar has been freed on police bail after spending a night in police detention.

However, she will have to report back to the police on April 16.

"I think its quite clear that my arrest is a blatant abuse of power by none other than the IGP and Prime Minister Najib Abdul Razak.

"The prime minister is responsible for allowing transgressions against Parliament," Nurul Izzah told reporters after her release.

She said Inspector-General of Police Khalid Abu Bakar ( right ) should be focusing on arresting hardcore criminals, instead of arresting dissenting voices.

She was also informed that her sister Nurul Nuha Anwar would be questioned next.

"Nurul Nuha will be questioned next and no one can escape this abuse by the IGP. He should be focusing on getting hardcore criminals, protecting Malaysia and getting Sirul, a convicted murderer, to atone for his sins," Nurul Izzah said.

Echoing her lawyer R Sivarasa, Nurul Izzah asserted that she has immunity granted under Article 63(2) of the Federal Constitution and thus should not be prosecuted for her speech.

Arrest an affront to her rights as MP

"It's such an onslaught and an affront to my rights, which will also affect the rights of other Members of Parliament, the greater issue of freedom of expression, which means highlighting of the key fundamental issues of the rakyat are put at stake.

"We're talking about an affront that has taken the democracy of Malaysia hostage," the PKR vice-president said.

Nurul Izzah said that there has never been anything like her arrest based on a speech made in Parliament since 1978.

"Since 1978 there has not ever been a Member of Parliament investigated. This a

crucial issue and will leave an impact on Malaysians," the eldest daughter of jailed Opposition Leader Anwar Ibrahim said.

She also pointed out that the actions of the government and the police are an "embarrassment and a complete betrayal of the trust of Malaysians".

Asked about the next course of action, Nurul Izzah said they will take this matter to court.

"We will take action. We will ensure that such an abuses will not continue under this regime," she stressed.

Repeating his client's stand, Sivarasa said Nurul Izzah's arrest was completely malicious and illegal.

"The excuse to go her house to get a copy of her speech was a complete bullshit. We could've given it to them should they have asked," he told reporters.

Other Pakatan Rakyat leaders and activists who have been detained for the Kita Lawan rally are PAS Youth treasurer Mohd Fakhrul Razi; PKR secretary-general Rafizi Ramli; Jingga 13 head coordinator Mohd Fariz Musa; PKR Youth chief Nik Nazmi Nik Ahmad; Kelana Jaya PKR Youth leader Saifullah Zulkifli; DAP Youth chief and MP for Rasah Teo Kok Seong; and activists Adam Adil Abdul Halim and Mandeep Singh.