The would-be buyers were an overseas-based consortium who made the approach last week, according to News Corp.
However, Charlesworth - who is feeling the heat from disgruntled fans after a horror first third of the season - scoffed at the claims.
“I get unsubstantiated offers all the time,” he said.
“The more serious ones want to relocate the club of course.”
The Englishman, who is in no immediate hurry to sell up, has just arrived back in the UK after spending Christmas in Australia, where he attended the home losses to Newcastle Jets and Perth Glory.
A group of fed-up fans unfurled a banner calling for him to go during the 4-1 New Year’s Eve defeat against Perth, whilst others booed him.
But Charlesworth has received the backing of the club’s former Championship and Premiership winner Patrick Zwaanswijk, who views him as more saviour than sinner.
“The owner stood up and saved the club when they were about to go under five years ago, and people should not forget that,” Zwaanswijk said.
“This is not just about him. Fans always say he’s not spending enough but it’s very hard to condemn him because he came in when the club was on its last legs and gave them a future.
“If he hadn’t the FFA would have been left in control and who knows what would’ve happened after that?”
Zwaanswijk, who spent three years as a player in Gosford and a season in charge of the youth Academy, claims what’s missing most is a definable “philosophy”, leaving the Mariners effectively rudderless since the departure of super coach Graham Arnold in 2014.
Friday’s 5-2 loss to Sydney FC was the ninth in 11 winless games this season, and another wooden spoon beckons.
“There seems to be a lack of communication and the lack of knowledge over how to run a professional (club),” he added.
“It’s a business and should be run as such by people who know everything there is to know. That’s where the Mariners are struggling a bit.
“When Graham Arnold was coach he had control over everything that was football related. He made all the decisions around the football side of things.
“They miss that sort of leadership as well as former CEO (and coach) Lawrie McKinna. It was a huge blow when he went to the Jets.
“He was very good at family and fan engagement, and selling the game to the people.”
While identifying a lack of philosophy, direction and structure from the top as key factors, Zwaanswijk, 43, said it was also about the coaches.
“In the end what you see on the field is always with the coaching staff,” he said.
“That’s how they want to play, who they recruit and the tactics they implement.
“I’ve played at big clubs (FC Utrecht and NAC Breda) and they had a philosophy.
“It should be the vision the club has that steers the coach, not the other way round.
“The easiest way is to say Mike Mulvey has to go but that’s not going to bring any solutions.
“We broke records in the past with a very good coach (Arnold) and a very good team. The coaches that come afterwards: Phil Moss, Tony Walmsley and Paul Okon haven’t really come so close.
“The club have also let a lot of talented players leave, most recently Lachlan Wales to Melbourne City, and those players have invariably done better wherever they’ve gone.
“I don’t understand why they have let so many players leave so easily.”
Zwaanswijk, now in charge of NSW NPL side Hills United, sued the Mariners when his two-year contract with the Academy was curtailed.
The matter was settled out of court and he insists there are no grudges and that he still goes to home games and wants to aid the club in any way he can.
“I was there in the pre-season and spoke to (coach) Mike Mulvey and I am more than happy to help out in someway at some point,” the Dutchman said.
“It’s just sad to see the club promising so much but not delivering over the past four years.
“People say it’s about money and that they don’t spend enough.
“But I don’t see it like that necessarily. Yes, they may not have the budget of a Sydney FC or Melbourne Victory in terms of bringing in marquee players.
“But when we won the Championship in 2013 we still had $600,000 left to spend (from the grants provided by FFA).
“What I see on the field is a team that wants to entertain but don’t seem to know how to win games anymore.
“They are all good individual players but it just doesn’t seem to gel between them.
“They want to entertain, they have plenty of possession but they aren’t creating enough chances.
“They need to put a better structure in place on and off the field.
“Maybe in four or five (years) you’ll have promotion and relegation.
“And if the Mariners don’t change in the meantime they could then be in real trouble.”
