By Julian Linden

AUGUSTA, Georgia (Reuters) - World number one Luke Donald was cleared to keep playing in the Masters after tournament officials investigated a mix-up over his score in Thursday's opening round.

The Englishman shot a three-over-par 75 in the first round but was initially listed on the scoreboards as having carded a 73 at Augusta National.

Officials ordered an investigation into the discrepancy but found that Donald had not been at fault because he had correctly signed his scorecard as a 75.

Had he signed for an incorrect score, Donald would have automatically been disqualified under the rules of golf.

Tournament officials said an administrative error had been made when they incorrectly entered his score into the official scoring system.

Instead of giving Donald him a bogey at the par-four fifth hole, the scorers had listed him as making a birdie.

"Just talked to Luke. Scorecard was correct," Donald's coach Patrick Goss tweeted. "Luke doesn't make that mistake. Too diligent and detailed."

Donald's wife also took to Twitter to express her relief: "Just got off the phone with Luke, NOT disqualified. Thank goodness."

Speaking to reporters before the investigation, Donald freely admitted he bogeyed the fifth hole and finished with a 75 and gave no indication that he was aware there was a mix-up.

"I three putted five and six and three over at that point and playing catch up. I didn't hit enough greens and give myself enough opportunity for birdies," he said.

"If I can go out tomorrow and get back in the red numbers hopefully I will be in the mix. I'm going to the range to work on my irons. I was a little bit off with those. I struggled with a bit with mud on the ball but everyone did."

(Editing by Frank Pingue)