Petro Matviyenko, deputy chief editor of the weekly "Novyy Styl" (New Style) in the eastern Ukrainian city of Kharkiv, told RFE/RL that investigators are not interested in finding Klymentyev.
Klymentyev, 66, has been missing since August 11.
Interior Minister Anatoliy Mohylyov said last week that Klymentyev was likely dead and that security forces are suspected of involvement in the disappearance.
Matviyenko said that the investigations cannot be unbiased, as he and Klymentyev were preparing articles about "the illegal activities of Kharkiv Oblast deputy prosecutor Serhiy Khachatrian."
According to Matviyenko, the police and prosecutor's office are connected, and therefore it is hard to believe that the investigation will shed any light on the case.
"The statements made by President [Viktor] Yanukovych and Interior Minister Mohylyov, saying that they have the investigations of Klymentyev's case under their personal control, are nothing but a PR action," Matviyenko said.
He called Klymentyev's case "Gongadzegate," an allusion to independent journalist Heorhiy Gongadze, who was abducted and beheaded by unknown assailants in 2000. Three former police officers were jailed for killing Gongadze, but it has not been established who ordered the killing.
Klymentyev's relatives reported him missing on August 12. Police said preliminary investigations revealed that Klymentyev was last seen on August 11 near Kharkiv's Sportivna subway station, together with an unknown man, and that both of them got into a BMW automobile.
Matviyenko said that on August 9, he and Klymentyev took photographs of mansions belonging to regional tax chief Stanislav Denisyuk and three other local officials, including a former Ukrainian Security Service officer. They intended to use the pictures in an article to be published in the next issue of the paper.
Matviyenko said he and Klymentyev met on the morning of August 11 to discuss the article and the photos. Later the same day, Matviyenko said, he was not able to reach Klymentyev by phone.
Today is the International Day of the Disappeared.