The chairman of Ghana's main opposition party was released on bail on Tuesday evening after being briefly detained in the capital, Accra.
Samuel Ofosu-Ampofo, who is from the National Democratic Congress (NDC), was held by police for about five hours, local news site GhanaWeb reports.
A police statement said there was "credible and actionable intelligence" making Mr Ofosu-Ampofo a suspect in recent acts of kidnapping.
Speaking after Mr Ofosu-Ampofo's release, a party official said the government was trying to intimidate the NDC.
The NDC chairman has not commented on the allegations.
JoyOnline has posted a video in which an unnamed party official says that the police had seized Mr Ofosu-Ampofo's electronic gadgets. But, he added, the NDC was happy to hand over the passwords as "we don't have anything to hide".
The NDC will continue to "fight the oppressor's rule" the official concluded.
