lies about late Michael Jackson's Estate worth

Michael Jackson was broke as a joke when he died ... so the IRS tax attack is showing a glaring ignorance ... so claim the people who run the MJ Estate.

Sources connected with the Estate tell TMZ ... they never suggested the Beatles catalog was worth ZERO -- to the contrary they agree it's worth around $1.5 BILLION.

That said ... sources say there's a reason they put a big fat zero in the Beatles column when they filed tax returns just after Michael died. They say there was a $700 million loan taken against the purchase of the catalog, bringing the net value to $800 million. Michael and Sony were 50/50 partners ... which means Michael's share was around $400 million.

Now the debt. Michael leveraged his interest to the hilt -- he borrowed $320 million against the catalog. And He owed another $200 million in personal debt ... And that's why they put ZERO.

One bone of contention -- although the Estate values the catalog at $1.5 billion, the IRS says it's DOUBLE that amount.

Estate sources say the IRS is also off base on the issue of MJ's likeness and image, which they valued at only $2,105 at the time he died. The IRS says it's worth more like $434 million.

Our sources say you have to look back at June, 2009. They say Michael made zilch on his likeness and image for the 15 YEARS before his death -- no commercials, not even T-shirts ... no one wanted to be associated with him -- at least commercially.

And finally ... as for the Jackson 5 music collection -- the Estate says it was worth $11.2 mil when Michael died ... the IRS says $45.5 mil.

So the sources say after settling up with Motown, MJ's interest was a lot less than people think. The Estate would gladly sell Michael's rights even today for $45.5 mil ... they say they'd sell it for $30 mil!