Nape was arrested last Saturday on allegations of attempting to bribe a rival candidate to drop out of the 2012 election in his province of Chimbu.
"Police have a constitutional duty to attend to complaints from citizens; in this case a candidate vying for Nape's Sinasina-Yongomugl seat laid a complaint with police," provincial police commander Augustine Wampe told The National Newspaper.
Nape, who denied all charges, was released on 2000 kina ($963) bail and is expected to appear in court after the election.
As Speaker he was instrumental in sowing the seeds of PNG's recent political crisis after he suddenly announced on August 2 last year the prime ministership was vacant.
The decision to allow a vote ousted incumbent PM Sir Michael Somare and elevated his former treasurer Peter O'Neill to the job.
Nape continued to preside over parliament but had a few more legislative grenades to throw.
In September he announced Sir Michael was no longer a member of the house, dumping the then 75-year-old "father of the nation" from the East Sepik electorate he had held for 44 years.
Sir Michael, now seemingly recovered from the heart surgery that made him an absent PM for much of 2010, is recontesting his seat.
In May, it was revealed the government's corruption watchdog had drawn up a warrant for Nape's arrest in relation to $2.4 million in missing development funds.
Nape denied those charges also. A month later he became acting governor-general.
In his brief stint in that job he also made waves, famously holding up the third swearing in of O'Neill and his cabinet for more than three hours as he negotiated behind closed doors with his parliamentary colleagues.