WELLINGTON (REUTERS) - A New Zealand lawmaker was given a security escort on Tuesday (May 21) after threats against her by white supremacists opposed to her views on hate speech, a rare precaution in a country where politicians mingle freely with the public.

A debate on hate speech has been raging in New Zealand since the mass shooting in Christchurch on March 15 by a suspected white supremacist that killed 51 people and wounded dozens.

Green party lawmaker Golriz Ghahraman, a human rights lawyer who was born in Iran and came to New Zealand as a child refugee, has seen an escalation of threats against her in recent weeks.

Ms Ghahraman would now be accompanied by a security escort when she leaves parliament, she told reporters on Tuesday, as the police deemed the threats were serious enough to warrant the extra security.

"It's distressing to have secret white supremacist groups talking about you," said Ms Ghahraman, who is among a handful of parliamentarians from ethnic minority communities.

"After Christchurch, New Zealand has asked us to be different. New Zealanders want us to debate issues robustly, but to keep personal attacks out of it. We have all learnt that words, including online posts, have consequences," she told reporters in parliament.

Ms Ghahraman has called for hate speech to be monitored, infuriating opponents, some of whom have accused her of trying to curb freedom.

Online threats have been more alarming.

The media group Newshub gave details in a report on white supremacy of threats in private online groups against Ms Ghahraman that included "hanging her like a lynch mob".

Questions have been asked since New Zealand's worst mass shooting about whether security agencies missed out on signs of white extremism and if enough resources were allocated to protect vulnerable communities.

Ms Ghahraman has told Reuters previously of death threats and xenophobia including being called a "terrorist" and "jihadist" online.

Politicians in New Zealand generally mingle freely with the public. The only leader to receive security is Prime Minister Jacinda Ardern.

People were shocked this year when a government minister was punched in the face while walking to work.

The country has been on heightened security alert since the Christchurch shootings.

In an attack broadcast live on Facebook, a lone gunman armed with semi-automatic weapons targeted Muslims attending Friday prayers at two mosques, killing 51 worshippers and wounding dozens of people.

Australian Brenton Tarrant has been charged with multiple counts of murder, and on Tuesday he was slapped with a new charge of engaging in a terrorist act.