CHANTILLY, Virginia — The sheriff in missing Pitt student Sudiksha Konanki’s hometown doesn’t believe that Joshua Riibe was complicit in her disappearance — though US investigators still want Dominican authorities to keep working the case.

Riibe was the last person to see Konanki, 20, alive after apparently meeting her at a bar in Punta Cana, where she was partying where with her girlfriends on a spring break trip on early March 6.

Dominican authorities have said he is a “person of interest” in the case and have put him under police guard and seized his passport.

However, the Loudon County Sheriff’s Office in Virginia sent investigators to the Dominican Republic and interviewed Riibe. As a result, detectives do not think he is responsible for her disappearance, Loudoun County Sheriff’s spokesman Thomas Julia told The Post.

Officials in Loudoun County, Va. will continue investigating the disappearance of Sudiksha Konanki via REUTERS

“Is he in any way complicit in any of this? And even if he’s not complicit in any way, and we don’t believe he is, we’ve interviewed him, and he was very cooperative,” Loudoun County Sheriff’s spokesman Thomas Julia exclusively told The Post.

“We believe he just struggles with his memory in the pre-dawn hours when you’re in a particular state of mind after going through a near-drowning yourself, you may indeed have passed out,” Julia said of Riibe.

Riibe, a 22-year-old college senior from Iowa, said he last saw Konanki while kissing her as the two swam in the ocean but soon after drunkenly passed out on the beach and could not say what happened to her.

Julia questioned how much time passed between when Riibe last saw Konanki to when he passed out — a key missing piece of information that would likely help investigators determine what happened to her.

“Was it a moment? Was it seconds? And that correspondingly bears on, could she have had a chance to get out and then somehow disappeared without his knowledge?” Julia said.

Loudoun County Sheriff’s spokesman Thomas Julia said there’s still evidence to be analyzed in the case. REUTERS

“So that’s why all of this is very important, to try to understand the exact timeline as best we can from his limited recollection,” he continued.

“If she really didn’t have any chance to get out and she did get washed out in a second wave, then all of this about ‘Might something else had happened to her if she did get out of the water that morning?’ becomes moot because it’s likely that never happened,” Julia said.

Even though Virginia officials in Konanki’s hometown don’t believe Riibe, who has not been accused of any wrongdoing, was directly involved, they’re pushing for the investigation to be completed by authorities in the Dominican Republic.

Konanki, 20, was last seen with Joshua Riibe the night she went missing.

“Anything that’s outstanding in terms of surveillance, phones, any other evidence that has been collected and hasn’t been analyzed, we would like all that completed,” Julia said. “We think this investigation and this family is owed the completion of the investigation.”

When asked what evidence or phone has not been analyzed, Julia said he couldn’t say but that they “haven’t seen 100% of the analysis yet.”

The Loudoun County Sheriff’s Office hopes authorities in the Dominican Republic close out their investigation, even after Konanki’s parents on Monday asked officials to declare her dead — despite authorities never finding her body.

Riibe, 22, said the last time he saw Konanki was in the ocean but that he passed out on the sand and couldn’t say what happened to her. Southeast technical college

“There’s no reason not to do that, even if they acknowledge and accept what the parents have said, there’s no reason for them not to complete this investigation so there’s no lingering ‘Oh, what about that phone? Oh, what about that piece of videotape?’” Julia said. “There’d be no reason not to complete the investigation.”

Konanki’s parents on Monday also suggested authorities should stop investigating Riibe, who was the last person to see the 20-year-old pre-med student alive on March 6.

“The individual last seen with her is cooperating with the investigation, and no evidence of foul play has been found,” the grieving parents wrote to local officials, without mentioning Riibe by name.

Konanki has been missing in the Dominican Republic since March 6. REUTERS

The two, who met sometime after Konanki arrived at the resort town, were seen in surveillance footage together the night she went missing.

Local authorities initially said they believed Konanki drowned in the ocean — but then said they were not ruling out foul play after Konanki’s family earlier raised fears that she could have been kidnapped.