A body has been found stuffed into a fish tank in the home of a man reported missing in July, San Francisco police have said.
The headless and handless corpse was so badly decomposed that it has not yet been identified or the cause of death established.
Officers had visited the home of Brian Egg, 65, several times after friends and family became concerned that they had not seen or heard from him since June.
But Police Commander Greg McEachern said that because there were no signs of foul play they had not forced entry to the property.
They were called again on 14 August by neighbours who had noticed the house had been sealed off by police tape and a private crime-scene cleaner and a stranger outside.
Officers reported a strong decaying odour and cleaning supplies inside and arrested the stranger, Robert McCaffrey, 52, on suspicion of homicide, identity theft and other charges.
After a two-day search cadaver dogs found a body stuffed in a fish tank in what Commander McEarchern described as a "concealed part of the home".
More from US
A second man Lance Silva, 39, has also been arrested and booked on suspicion of homicide and identity theft.
He is being held for an alleged parole violation, but Mr McCaffrey has been released after the San Francisco district attorney's office said it required more evidence to charge the men, including cause of death and the identity of the body found.