Amazon has joined Walmart in blaming Tesla's solar panels for causing fires on the roofs of their facilities, deteriorating confidence in Tesla’s embattled solar business, reports Forbes.

Amazon said the Tesla solar panels installed at one of its warehouses in Redlands, California, caught fire in June 2018.

According to the publication, the retail giant's disclosure came just days after Walmart sued Tesla for breach of contract and gross negligence.

Walmart asserts that seven of its stores experienced roof fires allegedly caused by the company's faulty solar panels.

Both companies later said they are working together to addressing all issues.

Yet the claims threaten to further erode Tesla’s solar business as the company is fighting to gain back market share, reports The Financial Post.

And Amazon has made one thing clear: it will not install any more Tesla panels.

Amazon fire was "isolated event", says Tesla

In a statement to Forbes, a Tesla spokesperson said that the Amazon fire was an “isolated event”.

“Tesla worked collaboratively with Amazon to root cause the event and remediate. We also performed inspections at the other sites, which confirmed the integrity of the systems," the publication quotes them commenting.

"As with all of our commercial solar installations, we continue to proactively monitor the systems to ensure they operate safely and reliably.”

However, according to a Business Insider report, Tesla was aware of problems related to its solar panels.

In the summer of 2018, Tesla launched a secret internal project called Project Titan. With the project, the company aimed to replace faulty “connectors” manufactured by Connecticut-based Amphenol, according to the report.

CEO Elon Musk hasn’t tweeted about the Walmart or Amazon complaints. But he has announced a revamped pricing plan in an effort to boost the slowing solar panel business, reports Forbes.

The new pricing model allows residents in six states to rent solar power systems starting at US$50 a month.

The scheme provides an alternative to buying them up front.