An "urgent notice" called on officials to provide details of "party members who have died in unusual circumstances" since 2012, according to posts on government and party websites in three provinces seen by AFP.
China's President Xi Jinping has touted a crackdown on graft since assuming the party's top post in 2012, and some officials have reportedly killed themselves to escape possible criminal proceedings and prevent the seizure of their ill- gotten assets, to the benefit of their families.
The Communist party is calling for a tally of deaths of officials at all levels, with details to be provided if the person was confirmed to have committed suicide, it added.
The survey requires suicides to be placed into several categories, one of which is "suspected of discipline violations", the party's standard euphemism for graft, it said.
The state-run China Daily said in September that Lou Xuequan, a former district Party chief in the eastern city of Nanjing, "reportedly hanged himself at his home" having been "dismissed from his position for accepting money as 'gifts'".
Critics say China has failed to implement institutional safeguards against graft such as public asset disclosure, an independent judiciary, and free media, leaving anti-corruption campaigns subject to the influence of politics.
Communist party academic Lin Zhe wrote in the China Daily last year that suicide has become a "judicial loophole for corrupt officials to escape punishment".
"Disciplinary and other investigations against a corrupt official... End in the event of their death," he wrote.
Officials who commit suicide "preserve their titles and honour, but also preserve the material gains they have made for their families, since their illegal income will no longer be confiscated", he added.
