ISLAMABAD, Pakistan — Fewer than a third of Pakistan’s members of Parliament file annual tax returns, according to a report published Wednesday, lending new focus to longstanding complaints from foreign donors and ordinary Pakistanis about tax evasion at the highest levels of society.

The report, jointly published by two civil society organizations, found that just 126 of the country’s 446 federal lawmakers filed annual income tax returns in 2011. Among those who did not file a return was President Asif Ali Zardari.