Image copyright Reuters Image caption Dr Haruko Obokata presented her findings in January

An investigation into a supposedly groundbreaking stem cell study in Japan has found the lead researcher guilty of misconduct.

The Riken Centre panel said Dr Haruko Obokata fabricated her work in an intentionally misleading fashion.

It said there were irregularities in data and images used in Dr Obokata's scientific papers published in Nature.

She stands by her claim to be able to produce stem cells using an acid bath or mechanical stress.

There were high hopes about the technique that promised to offer a cheap and ethical source of stem cells.

Stem cells can become any other type of tissue and are already being investigated to heal the damage caused by a heart attack and to restore sight to the blind.

But experts have been questioning Dr Obokata's findings and other research groups have failed to reproduce her results.

Image copyright SPL Image caption The scientist offered what appeared to be an easy way to create stem cells

Misleading

One of Dr Obokata's articles reused images related to her doctoral dissertation, which was based on different experiments.

"Actions like this completely destroy data credibility," Shunsuke Ishii, head of the Riken committee, told a news conference.

"There is no doubt that she was fully aware of this danger. We've therefore concluded this was an act of research misconduct involving fabrication."

In a statement, Dr Obokata said she would soon file a complaint with Riken, challenging the panel's findings.

"I'm filled with shock and indignation," she said. "If things stay as they are, misunderstanding could arise that the discovery of stap [stem] cells itself is forgery. That would be utterly unacceptable."