Many of you have been in touch to ask why Alexander Zverev has been seen using his phone multiple times during matches at this year’s Wimbledon – despite a ban on players doing so.

The reason is because Zverev is type 1 diabetic, and therefore has a medical exemption from the rule in order to check his glucose levels.

The All England Club has told BBC Sport that Grand Slam tournaments have a list of players that are diabetic, and those players are permitted to use their phones during matches in order to monitor their glucose and inject insulin if needed.

Zverev, who has reached the men’s singles final, told BBC Sport he has two phones, one of which contains no SIM card as it is solely used for monitoring his glucose while on court.

It means he can simply read the levels that his glucose monitor is relaying to his phone screen, instead of doing constant finger-prick checks.

“That’s why the umpires allow me to check my phone, so I don’t have to poke my finger every changeover,” he said.

A malfunction with Zverev’s monitor during the Halle Open in June led to him injecting a much higher level of insulin than needed during his semi-final loss to Taylor Fritz.

He said the mistake left him feeling “absolutely terrible” as he had to consume about 350g of sugar to counteract the high dose of insulin.

For all other players that do not have a medical exemption, the LTA states that mobile phones must be “switched off and stored away before entering the court” and kept out of sight of both the players and the umpire.

There is also a complete ban on the wearing or presence of smart watches or similar devices on court.

Some players have also been told to remove fitness trackers at certain tournaments.

Breaking these rules may lead to “immediate dismissal from the tournament and cause a report to be sent to the governing officiating body who can initiate a formal investigation into the incident”.

This article is the latest from BBC Sport’s Ask Me Anything team.