Topeka ? A Kansas Bureau of Investigation review of a 21-year-old man’s drowning could take up to six weeks, a top KBI official said Tuesday.

Deputy Director Kyle Smith gave that estimate a day after authorities recovered the body of Ebben Wright from Lake Shawnee. Wright had been missing for six days after he went into the water while boating with four acquaintances last week.

Smith said the KBI won’t close its investigation until it has a report on whether Wright’s body showed any traces of alcohol or other drugs.

Shawnee County Sheriff Dick Barta acknowledged Monday that he had asked for the KBI review, at the request of Wright’s family. Barta and other local authorities have said evidence they’ve gathered suggests Wright’s death was an accident.

Others on the boat told authorities that Wright jumped in the water to retrieve a safety flag, slipping out of a life jacket.

But Wright’s father and other relatives have suggested the sheriff’s department hasn’t been thorough – something Barta disputed.

“He’s afraid of water,” the father, Timothy Wright, of Detroit, told reporters Monday. “There is no way he would jump into a lake.”

Family members and local civil rights activists have noted Wright was black, while the other boaters were white, as is the sheriff.

But Barta said the accounts of Wright’s acquaintances on the boat and other witnesses are consistent in suggesting an accident.