Nick Kyrgios
Nick Kyrgios has been accused of deliberately tanking in Shanghai Getty Images

Controversial Australian tennis star Nick Kyrgios reverted to his 'tanking' ways at the Shanghai Masters on Wednesday (12 October), as he tamely conceded victory to qualifier Mischa Zverev. The 21-year-old was trailing 3-1 in the first set when he deliberately hit a lacklustre serve and returned to his chair before the ball had even been returned over the net.

At that point, Kyrgios was heard to say to the chair umpire: "Can you call time so I can finish this match and go home?" Kyrgios was warned by the umpire about his conduct and subsequently appeared to put in a little more effort in the following game, although he still continued to play well below his capability, eventually losing the match 6-3, 6-1.

The bizarre scenes came shortly after Kyrgios claimed he was "bored" during his straight-sets win over Sam Querrey at the Shangahi Masters. The outspoken Australian won the match on Tuesday (11 October) 6-4, 6-4 in just 53 minutes and subsequently said, according to the Daily Mail: "I was just a little bit bored at times. I was feeling very tired today.

"I didn't have the greatest sleep last night and obviously got in late the day before, and the ride to the courts isn't great either. It was just tough. I'm just tired today, so maybe I just wanted to get the job done."

It's not the first time the Australian has caused controversy, leading some to question his attitude. Last year Kyrgios enraged fans at Wimbledon when he appeared to deliberately play below his potential in his fourth-round loss to Richard Gasquet. The controversial star was booed by the crowd at SW19 for his perceived lack of effort, but subsequently insisted he had given his all.

In August 2015, Kyrgios was slapped with a suspended $10,000 fine with the threat of another $25,000 payment plus a 28-day ban after he linked fellow Australian pro Thanasi Kokkinakis to Stan Wawrinka's girlfriend during a match at the Montreal Masters. The Swiss star subsequently confronted Kyrgios in the locker room and urged the ATP to take action.

The punishments were all suspended for six months, with Kyrgios warned by the sport's governing body, the ATP, that he would face the punishment if he was fined for verbal or physical abuse, or if he was slapped with more than $5,000 in fines for any other reason.

Britain's Andy Murray subsequently insisted Kyrgios will have been "disappointed" with his performance, especially after he won the Japan Open earlier this month. He said, too, that contrary to previous suggestions, Kyrgios is enthusiastic about the sport.

"I didn't see the match today, I've heard a little bit about it," Murray explained to Sky Sports after his 6-3 6-2 win against Steve Johnson in Shanghai. "Nick will be disappointed obviously to have performed like that. I know he likes tennis, he knows a lot about the game and obviously had a great week last week [in Japan] and it is not easy to back it up in a different city the following week if you're feeling tired and a bit jaded.

"You've obviously got to give your best effort of what you have on that day. That is your job as a professional athlete is to give your best effort. If you're feeling sick maybe you're not going to play as well or perform as good but you have to give your best on the day."

Murray added: "That is something I've been trying to do; accepting when you're not feeling good, when you're a little bit stiff and sore or a little bit down you've just got to try and push through it and you'll feel much better after the match. If you go out and don't give your best it is tough to take that night, you feel pretty down about it."