"I'm disgusted with the way she has been treated," he said. "She could still afford [the rent] if she didn't have this unlawful deduction."
Miss Webster's rent went up 28 per cent last August, from $312.50 to $400 a week.
This came on top of a trip she took to a counselling conference in Britain as founder of a charitable trust, Sexual and Gender Education Services (Sages), which aims to support people with gender and sexuality issues.
A friend paid for her airfare, but she diverted money from another pension she receives from her former British employers to pay for other expenses, instead of paying her rent.
She was born in New Zealand but worked in Britain for three years in the 1960s, and again from 1973 to 1988.
Social Development Ministry figures show that the number of superannuitants and beneficiaries who also receive overseas pensions jumped by 40 per cent in the six years to 2010, from 42,336 to 59,309, because of growing immigration and New Zealanders returning to retire after working overseas. The numbers who also get Australian pensions leaped by almost 700 per cent, from 914 to 7248.
Ministry senior services head Warren Hudson said yesterday that 66,500, about one-ninth of the 600,000 people receiving NZ super and veteran's pensions, now also get overseas pensions.
Auckland University researchers Claire Dale and Susan St John said in a study last week that the current policy of paying full New Zealand Superannuation after 10 years of residence risked attracting retirees from countries with less generous systems including Australia, where the basic pension is means-tested.
"The richest Australian may immigrate to New Zealand, bringing their employment-based savings, and get the full NZ super," they said.
They recommended extending the residence requirement for NZ super to 25 years between the ages of 20 and 65, but allowing overseas pensions to be paid in full as taxable income on top of NZ super.
However, migrants and returnees from countries with which New Zealand has social security agreements, such as Britain, would still receive only one pension, normally NZ Super.