According to Sveriges Television, the police chief filed the complaint after learning that that ten months passed before police followed up a report about the possible abuse of the woman.
People who knew the couple saw how the man now in custody hit the woman with a crutch in November last year.
The incident was reported at the time, but police only launched an investigation into the matter last week.
The long delay in any follow up by police prompted the police chief to file the complaint.
Meanwhile, the investigation into the 58-year-old man now in custody was assigned a permanent prosecutor on Monday.
Prosecutor Klas Lorefors will now take on responsibility for pursuing the case, in which the man is suspected of holding his partner, an elderly woman reported to be suffering from multiple sclerosis, captive in a small cabin for the last nine years.
Lorefors’s first order of business is to meet with police and attempt to inspect the cabin where the couple lived for nearly a decade.
He also said he’s disappointed that the incident has attracted so much media coverage.
“Obviously, you want to be first to question a witness so that you get the spontaneous account of events, which makes it easier to evaluate its truthfulness,” Lorefors told the TT news agency.
Criminal inspector Christer Edlund from Eksjö agrees that witness testimony can be affected by the growing amount of information circulating in the media. But he doesn’t think that it could have been avoided if the police had interviewed more people over the weekend.
“The man is in custody and the woman is receiving care. If we have a murder, then we obviously are working over the weekend, but at some point we have to draw a line. We have limited resources,” Edlund told TT.
Overnight on Saturday, the camping area where the woman was held captive was subject to vandalism and graffiti.
As of yet, police have no suspects in the case.