The couple still plan to marry in 2020

The boyfriend of Japan's Princess Mako insisted Tuesday his family had no financial difficulties hanging over them, after reports of a unpaid loan apparently forced a postponement to a fairytale wedding between the two college sweethearts.

Kei Komuro and Mako, the eldest granddaughter of Emperor Akihito, had been scheduled to become formally engaged in a traditional Japanese court ceremony last year before a royal wedding planned in late 2018.

But the marriage was dramatically called off last February amid reports Komuro's family had run into financial difficulties, with his mother failing to repay a four-million-yen ($36,000) loan from a former fiance of hers.

In a statement released on Tuesday, Komuro said: "My mother and I both understand that the (financial) support from the ex-fiance of my mother has been settled."

Komuro said that when his mother and her fiance split up in 2012, the man had said the money he had offered them during the engagement did not need to be repaid.

But he changed his tune the year after, according to Komuro, demanding the money back in a letter in August 2013.

Komuro's mother met her former partner and told him she could not repay the money and there was no further request.

Komuro said he and his mother were then "bewildered" when reports surfaced in December 2017 that the ex-fiance still wanted his cash back, just two months after the royal engagement was announced.

"My mother and I both appreciate the support we received from the former fiance, and we will make efforts to gain understanding from him," Komuro's statement concluded.

However, the former fiance said Tuesday that the claim had not been settled.

"The money trouble has not been resolved and there has not been any contact from Mr. Komuro's side," he told the mass-circulation Yomiuri Shimbun.

- 'Clear the problem' -

In February 2018 the pair postponed the wedding until 2020, saying they needed more time to prepare, but rumours swirled in Japanese gossip magazines that there was more to the delay than simple money problems.

"We have come to realise that we do not have enough time to prepare for the ceremonies and our new life before the wedding planned in autumn," Mako said in a statement released through the imperial household agency at the time.

She said the announcement of their planned engagement was made "too hastily" after the news leaked out.

"We should have thought carefully whether the pace was actually right for us ... Now, we'd like to have the marriage, a major life event, in a better way."

She apologised to those planning the royal wedding, blaming the couple's "immaturity". They are both 27.

Mako's father Prince Akishino told reporters in November the pair "should take proper measures" if they still hope to get married.

Unless they "clear the problem", we cannot hold the ritual for a formal engagement, he said.

The Japanese royal family has a packed schedule this year, as the 85-year-old Emperor Akihito abdicates on April 30 -- the first time for more than two centuries that a Japanese emperor has stepped down.

His eldest son Naruhito is set to ascend the Chrysanthemum Throne a day later.

Mako is the eldest daughter of Prince Akishino, Naruhito's brother, and Princess Kiko.