A pensioner claiming to be a Catholic nun who sent envelopes containing white powder to parliamentary figures including Deputy Prime Minister Nick Clegg has been given a community order.

The 72-year-old woman, who is known as Sister Ruth Augustus, was found guilty of six counts of hoaxes involving noxious substances last month and has now been told she must serve a two-year community order with mental health treatment requirements.

The letters were intercepted at a mail screening centre last year and the powder was found to be non-hazardous, the Old Bailey heard. Augustus, of Leyton, accepted that she sent envelopes with letters in them but claimed police put the white powder in them.

Mark Kimsey, prosecuting, said three envelopes were intercepted at a mail screening centre in east London on June 17, last year.

One was addressed to Mr Clegg and on the envelope was written "devil worshipping", "freemason", "sex with 30 plus women".

The second was to Baroness Scotland, and had a swastika on it and two crosses, and "stop this evil devil worshipping". The third was to Baroness Kennedy, and was marked with a swastika, and "stop these evil devil worshipping freemasons".

The envelopes contained a gritty substance, but it was found they had already tested negative for anthrax, and specialist police who were called in found them to be non-hazardous.

On October 1 last year, three more envelopes were found, addressed to Mr Clegg, Lady Kennedy and MP Edward Leigh. The envelopes carried similar endorsements and slogans and contained white powder which was found to be non-hazardous.

On December 7, Augustus was arrested and told police: "I'm Sister Ruth, a 71-year-old disabled nun." She also said: "I look like a terrorist, don't I, working for a charity all over the world, with orphans? I'm not a Muslim terrorist, I'm a Catholic nun."

Asked why she had sent a letter to Mr Leigh, she said: "He's a Catholic, and goes to Westminster Cathedral." Of Mr Clegg, she said he "lied about all the tuition fees and everything else, keeping those Tory millionaires and rats in government". She added: "He boasted about all the women he's had sex with. He's an atheist singing hymns in the Albert Hall."