Saskatchewan NDP leader Ryan Meili is asking Premier Scott Moe if an investigation into Saskatchewan Party MLA Nadine Wilson will be sent to out-of-province Crown prosecutors.

An 87-year-old woman and her son say they were assaulted by Wilson, a veteran MLA, in March.

CBC News obtained documents confirming the Saskatchewan Rivers MLA has been interviewed by the Saskatoon Police Service (SPS). The documents say that SPS has concluded its investigation and the results have been passed to provincial Crown prosecutors to decide on possible charges.

Moe publicly commented on the case for the first time on Saturday.

"It's a personal matter and we will just leave that to her to work out," Moe said.

The complaints against Wilson were made by 87-year-old Lorraine Kingsley Helbig — who was married to Wilson's father until his recent death after the alleged incident — and Kingsley Helbig's son Eric Hocknes. It all stemmed from a bitter family estate dispute, according to the alleged victims.

According to the documents, the police investigation into the March 21 incident took slightly more than two weeks, but provincial Crown prosecutors have been reviewing the file for more than two months.

Ryan Meili said that because of Wilson's position, the decision to charge or not should be made out-of-province.

"When cases involve high profile figures you send that out-of-province to make sure that even the remotest perception, the possibility of political interference is avoided," Meili said.

Meili sent a letter to Moe last week asking if Wilson's role in caucus, on committees or as provincial secretary were affected by the investigation.

Meili said he wouldn't comment on the allegations against Wilson.

"The acts discussed are pretty serious allegations and for that reason should be addressed in a serious and independent way," he said.

Wilson's lawyer in Prince Albert did not respond to interview requests. Calls to Wilson's office were also not returned.